Multi-speed transmission having three planetary gear sets

ABSTRACT

A transmission includes an input member, an output member, three planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This divisional application claims the benefit of U.S. application Ser.No. 12/908,524, filed on Oct. 20, 2010, which is hereby incorporated inits entirety herein by reference.

FIELD

The invention relates generally to a multiple speed transmission havinga plurality of planetary gear sets and a plurality of torquetransmitting devices and more particularly to a transmission having sixor more speeds, three planetary gear sets and a plurality of torquetransmitting devices.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

A typical multiple speed transmission uses a combination of frictionclutches, planetary gear arrangements and fixed interconnections toachieve a plurality of gear ratios. The number and physical arrangementof the planetary gear sets, generally, are dictated by packaging, costand desired speed ratios.

While current transmissions achieve their intended purpose, the need fornew and improved transmission configurations which exhibit improvedperformance, especially from the standpoints of efficiency,responsiveness and smoothness and improved packaging, primarily reducedsize and weight, is essentially constant. Accordingly, there is a needfor an improved, cost-effective, compact multiple speed transmission.

SUMMARY

A transmission is provided having an input member, an output member,three planetary gear sets, a plurality of coupling members and aplurality of torque transmitting devices.

In one embodiment, the transmission includes an input member, an outputmember, first, second and third planetary gear sets each having first,second and third members, wherein the input and output members are eachinterconnected to at least one of the first, second, and third planetarygear sets. A first interconnecting member is continuouslyinterconnecting the second member of the first planetary gear set withthe first member of the second planetary gear set. A secondinterconnecting member is continuously interconnecting the third memberof the first planetary gear set with the second member of the secondplanetary gear set and with the first member of the third planetary gearset. Five torque transmitting mechanisms are each selectively engageableto interconnect at least one of the first, second and third members ofthe first, second and third planetary gear sets with at least one otherof the first, second, third members and a stationary member. The torquetransmitting mechanisms are selectively engageable in combinations of atleast two to establish at least six forward speed ratios and at leastone reverse speed ratio between the input member and the output member.

In another embodiment, a first of the five torque transmittingmechanisms is selectively engageable to interconnect the first member ofthe first planetary gear set with the second member of the thirdplanetary gear set.

In yet another embodiment, a second of the five torque transmittingmechanisms is selectively engageable to interconnect the second memberof the first planetary gear set and the first member of the secondplanetary gear set with the second member of the third planetary gearset.

In yet another embodiment, a third of the five torque transmittingmechanisms is selectively engageable to interconnect the third member ofthe first planetary gear set, the first member of the third planetarygear set, and the second member of the second planetary gear set withthe stationary member.

In yet another embodiment, a fourth of the five torque transmittingmechanisms is selectively engageable to interconnect the third member ofthe second planetary gear set with the stationary member.

In yet another embodiment, a fifth of the five torque transmittingmechanisms is selectively engageable to interconnect the second memberof the third planetary gear set with the stationary member.

In yet another embodiment, the first member of the first planetary gearset, the third member of the second planetary gear set and the firstmember of the third planetary gear set are sun gears, the second memberof the first planetary gear set, the first member of the secondplanetary gear set, and the second member of the third planetary gearset are carrier members and the third member of the first planetary gearset, the second member of the second planetary gear set and the thirdmember of the third planetary gear set are ring gears.

In yet another embodiment, the first member of the first planetary gearset, the third member of the second planetary gear set and the firstmember of the third planetary gear set are sun gears, the third memberof the first planetary gear set, the second member of the secondplanetary gear set, and the second member of the third planetary gearset are carrier members and the second member of the first planetarygear set, the first member of the second planetary gear set and thethird member of the third planetary gear set are ring gears.

In yet another embodiment, the first and second planetary gear sets arecombined into a planetary gear assembly wherein the second member of thesecond planetary gear set and the first interconnecting member areintegrated into the third member of the first planetary gear set and thefirst member of the second planetary gear set and a portion of thesecond interconnecting member are integrated into the second member ofthe first planetary gear set.

In yet another embodiment, the first member of the first planetary gearset, the third member of the second planetary gear set, and the firstmember of the third planetary gear set are sun gears, the first memberof the second planetary gear set and the second member of the firstplanetary gear set are a carrier member, the second member of the thirdplanetary gear set is a carrier member, the third member of the firstplanetary gear set and the second member of the second planetary gearset are a ring gear, and the third member of the third planetary gearset is a ring gear.

In yet another embodiment, the first member of the first planetary gearset, the third member of the second planetary gear set, and the firstmember of the third planetary gear set are sun gears, the second memberof the second planetary gear set and the third member of the firstplanetary gear set are a carrier member, the second member of the thirdplanetary gear set is a carrier member, the second member of the firstplanetary gear set and the first member of the second planetary gear setare a ring gear, and the third member of the third planetary gear set isa ring gear.

In yet another embodiment, the input member is continuouslyinterconnected to the first member of the first planetary gear set.

In yet another embodiment, the output member is continuouslyinterconnected to the third member of the third planetary gear set.

In yet another embodiment, the transmission includes an input member, anoutput member, a planetary gear set having first, second and thirdmembers, and a planetary gear assembly having first, second, third, andfourth members. An interconnecting member is continuouslyinterconnecting the fourth member of the planetary gear assembly withthe first member of the planetary gear set. A first torque transmittingmechanism is selectively engageable to interconnect the first member ofthe planetary gear assembly with the second member of the planetary gearset. A second torque transmitting mechanism is selectively engageable tointerconnect the third member of the planetary gear assembly with thesecond member of the planetary gear set. A third torque transmittingmechanism is selectively engageable to interconnect the fourth member ofthe planetary gear assembly and the first member of the planetary gearset with a stationary member. A fourth torque transmitting mechanism isselectively engageable to interconnect the second member of theplanetary gear assembly with the stationary member. A fifth torquetransmitting mechanism is selectively engageable to interconnect thesecond member of the planetary gear set with the stationary member. Thetorque transmitting mechanisms are selectively engageable incombinations of at least two to establish at least six forward speedratios and at least one reverse speed ratio between the input member andthe output member.

Further features, aspects and advantages of the present invention willbecome apparent by reference to the following description and appendeddrawings wherein like reference numbers refer to the same component,element or feature.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a lever diagram of an embodiment of a six speed transmissionaccording to the present invention;

FIG. 2 is a diagrammatic illustration of an embodiment of a six speedtransmission according to the present invention;

FIG. 3 is a diagrammatic illustration of another embodiment of a sixspeed transmission according to the present invention;

FIG. 4 is a diagrammatic illustration of yet another embodiment of a sixspeed transmission according to the present invention;

FIG. 5 is a diagrammatic illustration of yet another embodiment of a sixspeed transmission according to the present invention;

FIG. 6 is a diagrammatic illustration of yet another embodiment of a sixspeed transmission according to the present invention;

FIG. 7 is a diagrammatic illustration of still another embodiment of asix speed transmission according to the present invention;

FIG. 8 is a diagrammatic illustration of still another embodiment of asix speed transmission according to the present invention; and

FIG. 9 is a truth table presenting the state of engagement of thevarious torque transmitting elements in each of the available forwardand reverse speeds or gear ratios of the transmissions illustrated inFIGS. 1 through 8.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

At the outset, it should be appreciated that the embodiments of the sixspeed automatic transmission of the present invention have anarrangement of permanent mechanical connections between the elements ofthe three planetary gear sets. For example, a second component orelement of a first planetary gear set is permanently coupled to a firstcomponent or element of the second planetary gear set. A third componentor element of the first planetary gear set is permanently coupled to asecond component or element of the second planetary gear set. A thirdcomponent or element of the first planetary gear set is permanentlycoupled to a first component or element of the third planetary gear set.

Referring now to FIG. 1, an embodiment of a six speed transmission 10 isillustrated in a lever diagram format. A lever diagram is a schematicrepresentation of the components of a mechanical device such as anautomatic transmission. Each individual lever represents a planetarygear set wherein the three basic mechanical components of the planetarygear are each represented by a node. Therefore, a single lever containsthree nodes: one for the sun gear, one for the planet gear carrier, andone for the ring gear. The relative length between the nodes of eachlever can be used to represent the ring-to-sun ratio of each respectivegear set. These lever ratios, in turn, are used to vary the gear ratiosof the transmission in order to achieve an appropriate ratios and ratioprogression. Mechanical couplings or interconnections between the nodesof the various planetary gear sets are illustrated by thin, horizontallines and torque transmitting devices such as clutches and brakes arepresented as interleaved fingers. Further explanation of the format,purpose and use of lever diagrams can be found in SAE Paper 810102, “TheLever Analogy: A New Tool in Transmission Analysis” by Benford andLeising which is hereby fully incorporated by reference.

The transmission 10 includes an input shaft or member 12, a firstplanetary gear set 14 having three nodes: a first node 14A, a secondnode 14B and a third node 14C, a second planetary gear set 16 havingthree nodes: a first node 16A, a second node 16B and a third node 16Cand a third planetary gear set 18 having three nodes: a first node 18A,a second node 18B and an output shaft or member 22.

The input member 12 is continuously coupled to the first node 14A of thefirst planetary gear set 14. The output member 22 is coupled to thethird node 18C of the third planetary gear set 18. The second node 14Bof the first planetary gear set 14 is coupled to the first node 16A ofthe second planetary gear set 16. The third node 14C of the firstplanetary gear set 14 is coupled to the second node 16B of the thirdplanetary gear set 16. The third node 14C of the first planetary gearset 14 is also coupled to the first node 18A of the third planetary gearset 18.

A first clutch 26 selectively connects the first node 14A of the firstplanetary gear set 14 and the input member or shaft 12 with the secondnode 18B of the third planetary gear set 18. A second clutch 28selectively connects the second node 14B of the first planetary gear set14 and the first node 16A of the second planetary gear set 16 with thesecond node 18B of the third planetary gear set 18. A first brake 30selectively connects the second node 16B of the second planetary gearset 16 with a stationary member or transmission housing 50. A secondbrake 32 selectively connects third node 16C of the second planetarygear set 16 with a stationary member or transmission housing 50. A thirdbrake 34 selectively connects the second node 18B of the third planetarygear set 18 to a stationary member or transmission housing 50.

Referring now to FIG. 2, a stick diagram presents a schematic layout ofthe embodiment of the six speed transmission 10 according to the presentinvention. In FIG. 2, the numbering from the lever diagram of FIG. 1 iscarried over. The clutches and couplings are correspondingly presentedwhereas the nodes of the planetary gear sets now appear as components ofplanetary gear sets such as sun gears, ring gears, planet gears andplanet gear carriers.

For example, the planetary gear set 14 includes a sun gear member 14A, aring gear member 14C and a planet gear carrier member 14B that rotatablysupports a set of planet gears 14D (only one of which is shown). The sungear member 14A is connected for common rotation with a first shaft orinterconnecting member 42 and the input member or shaft 12. The ringgear member 14C is connected for common rotation with a second shaft orinterconnecting member 44 and a third shaft or interconnecting member46. The planet carrier member 14B is connected for common rotation witha fourth shaft or interconnecting member 48 and a fifth shaft orinterconnecting member 52. The planet gears 14D are each configured tointermesh with both the sun gear member 14A and the ring gear member14C.

The planetary gear set 16 includes a sun gear member 16C, a ring gearmember 16B and a planet gear carrier member 16A that rotatably supportsa first set of planet gears 16D (only one of which is shown) and asecond set of planet gears 16E (only one of which is shown). The sungear member 16C is connected for common rotation with the sixth shaft orinterconnecting member 54. The ring gear member 16B is connected forcommon rotation with the second shaft or interconnecting member 44 and aseventh shaft or interconnecting member 56. The planet carrier member16A is connected for common rotation with the fourth shaft orinterconnecting member 48. The first set of planet gears 16D are eachconfigured to intermesh with both the ring gear member 16B and secondset of planet gears 16E. The second set of planet gears 16E are eachconfigured to intermesh with both the sun gear member 16C and first setof planet gears 16D.

The planetary gear set 18 includes a sun gear member 18A, a ring gearmember 18C and a planet gear carrier member 18B that rotatably supportsa set of planet gears 18D (only one of which is shown). The sun gearmember 18A is connected for common rotation with the third shaft orinterconnecting member 46. The ring gear member 18C is connected forcommon rotation with output member or shaft 22. The planet carriermember 18B is connected for common rotation with the eighth shaft orinterconnecting member 58 and a ninth shaft or interconnecting member60. The planet gears 18D are each configured to intermesh with both thesun gear member 18A and the ring gear member 18C.

The input shaft or member 12 is continuously connected to an engine (notshown) or to a turbine of a torque converter (not shown). The outputshaft or member 22 is continuously connected with the final drive unitor transfer case (not shown).

The torque-transmitting mechanisms or clutches 26, 28 and brakes 30, 32and 34 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 26 is selectively engageable toconnect the first shaft or interconnecting member 42 and the input shaftor member 12 with the ninth shaft or interconnecting member 60. Thesecond clutch 28 is selectively engageable to connect the fifth shaft orinterconnecting member 52 with the ninth shaft or interconnecting member60. The first brake 30 is selectively engageable to connect the seventhshaft or interconnecting member 56 with a stationary element or thetransmission housing 50 in order to restrict the member 56 from rotatingrelative to the transmission housing 50. The second brake 32 isselectively engageable to connect the sixth shaft or interconnectingmember 54 with the stationary element or the transmission housing 50 inorder to restrict the member 54 from rotating relative to thetransmission housing 50. The third brake 34 is selectively engageable toconnect the eighth shaft or interconnecting member 58 with thestationary element or the transmission housing 50 in order to restrictthe member 58 from rotating relative to the transmission housing 50.

Referring now to FIG. 3, a schematic layout of another embodiment of thesix speed transmission according to the present invention is illustratedand referenced as 100. In the present embodiment, the planetary gearsets 114 and 116 of transmission 100 share a common carrier member 117that rotatably supports a first set of planet gears 114D (only one ofwhich is shown) and a second set of planet gears 116D (only one of whichis shown). Further, the planetary gear set 114 includes a sun gearmember 114A and a ring gear member 114C and the planetary gear set 116includes a sun gear member 116C. The sun gear member 114A is connectedfor common rotation with a first shaft or interconnecting member 142 andthe input member or shaft 112. The ring gear member 114C is connectedfor common rotation with a second shaft or interconnecting member 144and a third shaft or interconnecting member 146. The planet carriermember 117 is connected for common rotation with a fourth shaft orinterconnecting member 148. The first set of planet gears 114D are eachconfigured to intermesh with each of the sun gear member 114A, the ringgear member 114C and the second set of planet gears 116D. The second setof planet gears 116D are each configured as long pinions that intermeshwith both the sun gear member 116C of planetary gear set 116 and thefirst set of planet gears 114D of planetary gear set 114. The sun gearmember 116C is connected for common rotation with the fifth shaft orinterconnecting member 152.

The planetary gear set 118 includes a sun gear member 118A, a ring gearmember 118C and a planet gear carrier member 118B that rotatablysupports a set of planet gears 118D (only one of which is shown). Thesun gear member 118A is connected for common rotation with the thirdshaft or interconnecting member 146. The ring gear member 118C isconnected for common rotation with output member or shaft 122. Theplanet carrier member 118B is connected for common rotation with thesixth shaft or interconnecting member 154 and a seventh shaft orinterconnecting member 156. The planet gears 118D are each configured tointermesh with both the sun gear member 118A and the ring gear member118C.

The input shaft or member 112 is continuously connected to an engine(not shown) or to a turbine of a torque converter (not shown). Theoutput shaft or member 122 is continuously connected with the finaldrive unit or transfer case (not shown).

The torque-transmitting mechanisms or clutches 126, 128 and brakes 130,132 and 134 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 126 is selectively engageable toconnect the first shaft or interconnecting member 142 and the inputshaft or member 112 with the sixth shaft or interconnecting member 154and the seventh shaft or interconnecting member 156. The second clutch128 is selectively engageable to connect the fourth shaft orinterconnecting member 148 with the sixth shaft or interconnectingmember 154 and the seventh shaft or interconnecting member 156. Thefirst brake 130 is selectively engageable to connect the second shaft orinterconnecting member 144 and third shaft or interconnecting member 146with a stationary element or the transmission housing 150 in order torestrict the members 144, 146 from rotating relative to the transmissionhousing 150. The second brake 132 is selectively engageable to connectthe fifth shaft or interconnecting member 152 with the stationaryelement or the transmission housing 150 in order to restrict the member152 from rotating relative to the transmission housing 150. The thirdbrake 134 is selectively engageable to connect the sixth shaft orinterconnecting member 154 and the seventh shaft or interconnectingmember 156 with the stationary element or the transmission housing 150in order to restrict the members 154, 156 from rotating relative to thetransmission housing 150.

Referring now to FIG. 4, a transmission 100′ is illustrated in schematicform. Transmission 100′ has the same planetary gear sets 114, 116 and118 and clutches 126, 128 and brakes 130, 132 and 134 as provided intransmission 100. However, the spacial arrangement of transmission 100′differs from spacial arrangement of transmission 100. More specifically,planetary gear sets 114, 116 of transmission 100′ are adjacent the ends180 and 182 of the input and output shafts 112, 122. In contrast,planetary gear set 118 in transmission 100 is disposed between planetarygear sets 114, 116 and the ends 180 and 182 of the input and outputshafts 112, 122 of transmission 100.

Referring now to FIG. 5, a schematic layout of another embodiment of thesix speed transmission according to the present invention is illustratedand referenced as 200. In the present embodiment, the planetary gearsets 214 and 216 of transmission 200 share a common carrier member 217that rotatably supports a first set of planet gears 214D (only one ofwhich is shown) and a second set of planet gears 216D (only one of whichis shown). Further, the planetary gear set 214 includes a sun gearmember 214A and the planetary gear set 216 includes a sun gear member216C and a ring gear member 216B. The sun gear member 214A is connectedfor common rotation with a first shaft or interconnecting member 242 andthe input member or shaft 212. The planet carrier member 217 isconnected for common rotation with a second shaft or interconnectingmember 244. The first set of planet gears 214D are each configured aslong pinion gears that intermesh with each of the sun gear member 214A,the ring gear member 216B and the second set of planet gears 216D. Thesecond set of planet gears 216D are each configured intermesh with boththe sun gear member 216C of planetary gear set 216 and the first set ofplanet gears 214D of planetary gear set 214. The sun gear member 216C isconnected for common rotation with a third shaft or interconnectingmember 246. The ring gear member 216B is connected for common rotationwith a fourth shaft or interconnecting member 248 and a fifth shaft orinterconnecting member 252.

The planetary gear set 218 includes a sun gear member 218A, a ring gearmember 218C and a planet gear carrier member 218B that rotatablysupports a set of planet gears 218D (only one of which is shown). Thesun gear member 218A is connected for common rotation with the fifthshaft or interconnecting member 252. The ring gear member 218C isconnected for common rotation with output member or shaft 222. Theplanet carrier member 218B is connected for common rotation with thesixth shaft or interconnecting member 254 and a seventh shaft orinterconnecting member 256. The planet gears 218D are each configured tointermesh with both the sun gear member 218A and the ring gear member218C.

The input shaft or member 212 is continuously connected to an engine(not shown) or to a turbine of a torque converter (not shown). Theoutput shaft or member 222 is continuously connected with the finaldrive unit or transfer case (not shown).

The torque-transmitting mechanisms or clutches 226, 228 and brakes 230,232 and 234 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 226 is selectively engageable toconnect the first shaft or interconnecting member 242 and the inputshaft or member 212 with the sixth shaft or interconnecting member 254and the seventh shaft or interconnecting member 256. The second clutch228 is selectively engageable to connect the second shaft orinterconnecting member 244 with the sixth shaft or interconnectingmember 254 and the seventh shaft or interconnecting member 256. Thefirst brake 230 is selectively engageable to connect the fourth shaft orinterconnecting member 248 and fifth shaft or interconnecting member 252with a stationary element or the transmission housing 250 in order torestrict the members 248, 252 from rotating relative to the transmissionhousing 250. The second brake 232 is selectively engageable to connectthe third shaft or interconnecting member 246 with the stationaryelement or the transmission housing 250 in order to restrict the member246 from rotating relative to the transmission housing 250. The thirdbrake 234 is selectively engageable to connect the sixth shaft orinterconnecting member 254 and the seventh shaft or interconnectingmember 256 with the stationary element or the transmission housing 250in order to restrict the members 254, 256 from rotating relative to thetransmission housing 250.

Referring now to FIG. 6, a schematic layout of another embodiment of thesix speed transmission according to the present invention is illustratedand referenced as 300. In the present embodiment, the planetary gear set314 includes a sun gear member 314A, a ring gear member 314B and aplanet gear carrier member 314C that rotatably supports a first set ofplanet gears 314D (only one of which is shown) and a second set ofplanet gears 314E (only one of which is shown). The sun gear member 314Ais connected for common rotation with an input shaft or interconnectingmember 312. The ring gear member 314B is connected for common rotationwith the first shaft or interconnecting member 342 and a second shaft orinterconnecting member 344. The planet carrier member 314C is connectedfor common rotation with a third shaft or interconnecting member 346 anda fourth shaft or interconnecting member 348. The first set of planetgears 314D are each configured to intermesh with both the ring gearmember 314B and second set of planet gears 314E. The second set ofplanet gears 314E are each configured to intermesh with both the sungear member 314A and first set of planet gears 314D.

The planetary gear set 316 includes a sun gear member 316C, a ring gearmember 316A and a planet gear carrier member 316B that rotatablysupports a set of planet gears 316D (only one of which is shown). Thesun gear member 316C is connected for common rotation with a fifth shaftor interconnecting member 352. The ring gear member 316A is connectedfor common rotation with the first shaft or interconnecting member 342.The planet carrier member 316B is connected for common rotation with thethird shaft or interconnecting member 346 and a sixth shaft orinterconnecting member 354. The planet gears 316D are each configured tointermesh with both the sun gear member 316C and the ring gear member316A.

The planetary gear set 318 includes a sun gear member 318A, a ring gearmember 318C and a planet gear carrier member 318B that rotatablysupports a set of planet gears 318D (only one of which is shown). Thesun gear member 318A is connected for common rotation with the fourthshaft or interconnecting member 348. The ring gear member 318C isconnected for common rotation with output member or shaft 322. Theplanet carrier member 318B is connected for common rotation with aseventh shaft or interconnecting member 356 and an eighth shaft orinterconnecting member 358. The planet gears 318D are each configured tointermesh with both the sun gear member 318A and the ring gear member318C.

The input shaft or member 312 is continuously connected to an engine(not shown) or to a turbine of a torque converter (not shown). Theoutput shaft or member 322 is continuously connected with the finaldrive unit or transfer case (not shown).

The torque-transmitting mechanisms or clutches 326, 328 and brakes 330,332 and 334 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 326 is selectively engageable toconnect the input shaft or member 312 with the eighth shaft orinterconnecting member 358. The second clutch 328 is selectivelyengageable to connect the second shaft or interconnecting member 344with the seventh shaft or interconnecting member 356. The first brake330 is selectively engageable to connect the sixth shaft orinterconnecting member 354 with a stationary element or the transmissionhousing 350 in order to restrict the member 354 from rotating relativeto the transmission housing 350. The second brake 332 is selectivelyengageable to connect the fifth shaft or interconnecting member 352 withthe stationary element or the transmission housing 350 in order torestrict the member 352 from rotating relative to the transmissionhousing 350. The third brake 334 is selectively engageable to connectthe seventh shaft or interconnecting member 356 with the stationaryelement or the transmission housing 350 in order to restrict the member356 from rotating relative to the transmission housing 350.

Referring now to FIG. 7, a schematic layout of another embodiment of thesix speed transmission according to the present invention is illustratedand referenced as 400. In the present embodiment, the planetary gearsets 414 and 416 of transmission 400 share a common carrier member 417that rotatably supports a first set of planet gears 414D (only one ofwhich is shown) and a second set of planet gears 416D (only one of whichis shown). Further, the planetary gear set 414 includes a sun gearmember 414A and the planetary gear set 416 includes a sun gear member416C and a ring gear member 416A. The sun gear member 414A is connectedfor common rotation with a first shaft or interconnecting member 442 andthe input member or shaft 412. The planet carrier member 417 isconnected for common rotation with a second shaft or interconnectingmember 444 and to a third shaft or interconnecting member 446. The firstset of planet gears 414D are each configured as long pinion gears thatintermesh with both the sun gear member 414A and the second set ofplanet gears 416D. The second set of planet gears 416D are eachconfigured intermesh with both the sun gear member 416C of planetarygear set 416, ring gear member 416A and the first set of planet gears414D of planetary gear set 414. The sun gear member 416C is connectedfor common rotation with a fourth shaft or interconnecting member 448.The ring gear member 416A is connected for common rotation with a fifthshaft or interconnecting member 452.

The planetary gear set 418 includes a sun gear member 418A, a ring gearmember 418C and a planet gear carrier member 418B that rotatablysupports a set of planet gears 418D (only one of which is shown). Thesun gear member 418A is connected for common rotation with the secondshaft or interconnecting member 444. The ring gear member 418C isconnected for common rotation with output member or shaft 422. Theplanet carrier member 418B is connected for common rotation with thesixth shaft or interconnecting member 454 and a seventh shaft orinterconnecting member 456. The planet gears 418D are each configured tointermesh with both the sun gear member 418A and the ring gear member418C.

The input shaft or member 412 is continuously connected to an engine(not shown) or to a turbine of a torque converter (not shown). Theoutput shaft or member 422 is continuously connected with the finaldrive unit or transfer case (not shown).

The torque-transmitting mechanisms or clutches 426, 428 and brakes 430,432 and 434 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 426 is selectively engageable toconnect the first shaft or interconnecting member 442 and the inputshaft or member 412 with the sixth shaft or interconnecting member 454and the seventh shaft or interconnecting member 456. The second clutch428 is selectively engageable to connect the fifth shaft orinterconnecting member 452 with the seventh shaft or interconnectingmember 456. The first brake 430 is selectively engageable to connectsecond shaft or interconnecting member 444 and the third shaft orinterconnecting member 446 with a stationary element or the transmissionhousing 450 in order to restrict the members 444, 446 from rotatingrelative to the transmission housing 450. The second brake 432 isselectively engageable to connect the fourth shaft or interconnectingmember 448 with the stationary element or the transmission housing 450in order to restrict the member 448 from rotating relative to thetransmission housing 450. The third brake 434 is selectively engageableto connect the sixth shaft or interconnecting member 454 and the seventhshaft or interconnecting member 456 with the stationary element or thetransmission housing 450 in order to restrict the members 454, 456 fromrotating relative to the transmission housing 450.

Referring now to FIG. 8, a schematic layout of another embodiment of thesix speed transmission according to the present invention is illustratedand referenced as 500. In the present embodiment, the planetary gearsets 514 and 516 of transmission 500 share a common carrier member 517that rotatably supports a first set of planet gears 514D (only one ofwhich is shown) and a second set of planet gears 516D (only one of whichis shown). Further, the planetary gear set 514 includes a sun gearmember 514A and a ring gear member 514C and the planetary gear set 516includes a sun gear member 516C. The sun gear member 514A is connectedfor common rotation with a first shaft or interconnecting member 542 andthe input member or shaft 512. The ring gear member 514C is connectedfor common rotation with a second shaft or interconnecting member 544.The planet carrier member 517 is connected for common rotation with athird shaft or interconnecting member 546 and a fourth shaft orinterconnecting member 548. The first set of planet gears 514D are eachconfigured to intermesh with both the sun gear member 514A and thesecond set of planet gears 516D. The second set of planet gears 516D areeach configured as long pinions that intermesh with each of the sun gearmember 516C of planetary gear set 516, the ring gear member 514C and thefirst set of planet gears 514D of planetary gear set 514. The sun gearmember 516C is connected for common rotation with the fifth shaft orinterconnecting member 552.

The planetary gear set 518 includes a sun gear member 518A, a ring gearmember 518C and a planet gear carrier member 518B that rotatablysupports a set of planet gears 518D (only one of which is shown). Thesun gear member 518A is connected for common rotation with the fourthshaft or interconnecting member 548. The ring gear member 518C isconnected for common rotation with output member or shaft 522. Theplanet carrier member 518B is connected for common rotation with thesixth shaft or interconnecting member 554 and a seventh shaft orinterconnecting member 556. The planet gears 518D are each configured tointermesh with both the sun gear member 518A and the ring gear member518C.

The input shaft or member 512 is continuously connected to an engine(not shown) or to a turbine of a torque converter (not shown). Theoutput shaft or member 522 is continuously connected with the finaldrive unit or transfer case (not shown).

The torque-transmitting mechanisms or clutches 526, 528 and brakes 530,532 and 534 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing. For example, the first clutch 526 is selectively engageable toconnect the first shaft or interconnecting member 542 and the inputshaft or member 512 with the sixth shaft or interconnecting member 554and the seventh shaft or interconnecting member 556. The second clutch528 is selectively engageable to connect the second shaft orinterconnecting member 544 with the sixth shaft or interconnectingmember 554 and the seventh shaft or interconnecting member 556. Thefirst brake 530 is selectively engageable to connect the third shaft orinterconnecting member 546 and fourth shaft or interconnecting member548 with a stationary element or the transmission housing 550 in orderto restrict the members 546, 548 from rotating relative to thetransmission housing 550. The second brake 532 is selectively engageableto connect the fifth shaft or interconnecting member 552 with thestationary element or the transmission housing 550 in order to restrictthe member 552 from rotating relative to the transmission housing 550.The third brake 534 is selectively engageable to connect the sixth shaftor interconnecting member 554 and the seventh shaft or interconnectingmember 556 with the stationary element or the transmission housing 550in order to restrict the members 554, 556 from rotating relative to thetransmission housing 550.

Referring now to FIG. 2 through FIG. 9, the operation of the embodimentsof the six speed transmission of the present invention will bedescribed. It will be appreciated that transmissions 10, 100, 100′, 200,300, 400 and 500 are capable of transmitting torque from the input shaftor member to the output shaft or member in at least six forward speed ortorque ratios and at least one reverse speed or torque ratio with tripleoverdrive. Each forward and reverse speed or torque ratio is attained byengagement of one or more of the torque-transmitting mechanisms, as willbe explained below. FIG. 9 is a truth table presenting the variouscombinations of torque-transmitting mechanisms that are activated orengaged to achieve the various gear states. An “X” in the box means thatthe particular clutch or brake is engaged to achieve the desired gearstate. An “O” represents that the particular torque transmitting device(i.e. a brake or clutch) is on or active, but not carrying torque.Actual numerical gear ratios of the various gear states are alsopresented although it should be appreciated that these numerical valuesare exemplary only and that they may be adjusted over significant rangesto accommodate various applications and operational criteria of thetransmissions of the present invention. Examples of the gear ratios thatmay be obtained using the embodiments of the present invention are alsoshown in FIG. 9. Of course, other gear ratios are achievable dependingon the gear diameter, gear teeth count and gear configuration selected.

For example, to establish a reverse gear, the second brake (i.e. 32,132, 232, 332, 432, and 532) and third brake (i.e. 34, 134, 234, 334,434, and 534) are engaged or activated. Brakes (32, 132, 232, 332, 432,and 532) and (34, 134, 234, 334, 434, and 534) connect variousinterconnecting members and members of the planetary gear sets to thetransmission housing, as described above with respect to the embodimentsof the present invention. Likewise, the six forward ratios are achievedthrough different combinations of clutch and brake engagement, as shownin FIG. 9.

It will be appreciated that the foregoing explanation of operation andgear states of the six speed transmissions 10, 100, 100′, 200, 300, 400and 500 assumes, first of all, that all the clutches not specificallyreferenced in a given gear state are inactive or disengaged and, secondof all, that during gear shifts, i.e., changes of gear state, between atleast adjacent gear states, a clutch engaged or activated in both gearstates will remain engaged or activated.

The transmission of the present invention has many advantages andbenefits over the prior art, for example, the present inventioncontemplates that transmissions disclosed above may be configured forboth front wheel and rear wheel drive vehicles.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

The following is claimed:
 1. A transmission comprising: an input member;an output member; first, second and third planetary gear sets eachhaving first, second and third members, wherein the input member iscontinuously interconnected to the first member of the first planetarygear set and the output member is continuously interconnected to thethird member of the third planetary gear set; a first interconnectingmember continuously interconnecting the second member of the firstplanetary gear set with the first member of the second planetary gearset; a second interconnecting member continuously interconnecting thethird member of the first planetary gear set with the second member ofthe second planetary gear set; a third interconnecting membercontinuously interconnecting the third member of the first planetarygear set with the first member of the third planetary gear set; and fivetorque transmitting mechanisms each selectively engageable tointerconnect at least one of the first, second and third members of thefirst, second and third planetary gear sets with at least one other ofthe first, second, third members and a stationary member, and whereinthe torque transmitting mechanisms are selectively engageable incombinations of at least two to establish at least six forward speedratios and at least one reverse speed ratio between the input member andthe output member.
 2. The transmission of claim 1 wherein a first of thefive torque transmitting mechanisms is selectively engageable tointerconnect the first member of the first planetary gear set with thesecond member of the third planetary gear set.
 3. The transmission ofclaim 2 wherein a second of the five torque transmitting mechanisms isselectively engageable to interconnect the second member of the firstplanetary gear set and the first member of the second planetary gear setwith the second member of the third planetary gear set.
 4. Thetransmission of claim 3 wherein a third of the five torque transmittingmechanisms is selectively engageable to interconnect the third member ofthe first planetary gear set, the first member of the third planetarygear set, and the second member of the second planetary gear set withthe stationary member.
 5. The transmission of claim 4 wherein a fourthof the five torque transmitting mechanisms is selectively engageable tointerconnect the third member of the second planetary gear set with thestationary member.
 6. The transmission of claim 5 wherein a fifth of thefive torque transmitting mechanisms is selectively engageable tointerconnect the second member of the third planetary gear set with thestationary member.
 7. The transmission of claim 6 wherein the firstmember of the first planetary gear set, the third member of the secondplanetary gear set, and the first member of the third planetary gear setare sun gears, the first and second planetary gear sets include acarrier member that includes the second member of the first planetarygear set, the first member of the second planetary gear set, and thefirst interconnecting member, and the second planetary gear set includesa ring gear that includes the third member of the first planetary gearset, the first member of the second planetary gear set, and the secondinterconnecting member, the second member of the fourth planetary gearset is a carrier member, and the third member of the fourth planetarygear set is a ring gear.
 8. The transmission of claim 1 wherein thefirst member of the first planetary gear set, the third member of thesecond planetary gear set and the first member of the third planetarygear set are sun gears, the second member of the first planetary gearset, the first member of the second planetary gear set, and the secondmember of the third planetary gear set are carrier members, and thethird member of the first planetary gear set, the second member of thesecond planetary gear set, and the third member of the third planetarygear set are ring gears.
 9. The transmission of claim 8 wherein thetransmission includes a common carrier member and a common ring gear,the common carrier member including the carrier members of the first andsecond planetary gear sets and the first interconnecting member, and thecommon ring gear including the ring gears of the first and secondplanetary gear sets and the second interconnecting member.
 10. Thetransmission of claim 9 wherein the first planetary gear set includes aset of long pinion gears rotatably supported by the common carriermember and meshes with each of the sun gear of the first planetary gearset and the common ring gear.
 11. The transmission of claim 10 whereinthe second planetary gear set includes a set of short pinion gearsrotatably supported by the common carrier member and meshes with each ofthe sun gear of the second planetary gear set and the set of piniongears of the first planetary gear set.
 12. The transmission of claim 11wherein the first planetary gear set is disposed between the second andthe third planetary gear sets and the first, second, and fifth of thefive torque transmitting mechanisms are disposed between the firstplanetary gear set and the third planetary gear set.
 13. Thetransmission of claim 12 wherein the third and fourth torquetransmitting mechanisms are disposed at a first end of the transmissionadjacent the second planetary gear set.
 14. A transmission comprising:an input member; an output member; first, second and third planetarygear sets each having first, second and third members, wherein the inputmember is continuously interconnected to the first member of the firstplanetary gear set and the output member is continuously interconnectedto the third member of the third planetary gear set; threeinterconnecting members each selectively engageable to interconnect oneof the first, second and third members of the first, second and thirdplanetary gear sets with one other of the first, second, third membersof the first, second and third planetary gear sets; a first torquetransmitting mechanism selectively engageable to interconnect the firstmember of the first planetary gear set with the second member of thethird planetary gear set; a second torque transmitting mechanismselectively engageable to interconnect the first interconnecting memberwith the second member of the third planetary gear set; a third torquetransmitting mechanism selectively engageable to interconnect at leastone of the second interconnecting member and the third interconnectingmember with a stationary member; a fourth torque transmitting mechanismselectively engageable to interconnect the third member of the secondplanetary gear set with the stationary member; a fifth torquetransmitting mechanism selectively engageable to interconnect the secondmember of the third planetary gear set with the stationary member, andwherein the torque transmitting mechanisms are selectively engageable incombinations of at least two to establish at least six forward speedratios and at least one reverse speed ratio between the input member andthe output member.
 15. The transmission of claim 14 wherein a first ofthe three interconnecting members continuously interconnect the secondmember of the first planetary gear set with the first member of thesecond planetary gear set.
 16. The transmission of claim 15 wherein asecond of the three interconnecting members continuously interconnectsthe third member of the first planetary gear set with the second memberof the second planetary gear set.
 17. The transmission of claim 16wherein a third of the three interconnecting members continuouslyinterconnects the third member of the first planetary gear set with thefirst member of the third planetary gear set.
 18. The transmission ofclaim 17 wherein the first member of the first planetary gear set, thethird member of the second planetary gear set, and the first member ofthe third planetary gear set are sun gears, the first and secondplanetary gear sets include a carrier member that includes the secondmember of the first planetary gear set, the first member of the secondplanetary gear set, and the first interconnecting member, and the secondplanetary gear set includes a ring gear that includes the third memberof the first planetary gear set, the first member of the secondplanetary gear set, and the second interconnecting member, the secondmember of the fourth planetary gear set is a carrier member, and thethird member of the fourth planetary gear set is a ring gear.
 19. Thetransmission of claim 17 wherein the first member of the first planetarygear set, the third member of the second planetary gear set and thefirst member of the third planetary gear set are sun gears, the secondmember of the first planetary gear set, the first member of the secondplanetary gear set, and the second member of the third planetary gearset are carrier members, and the third member of the first planetarygear set, the second member of the second planetary gear set, and thethird member of the third planetary gear set are ring gears.
 20. Thetransmission of claim 19 wherein the transmission includes a commoncarrier member and a common ring gear, the common carrier memberincluding the carrier members of the first and second planetary gearsets and the first interconnecting member, and the common ring gearincluding the ring gears of the first and second planetary gear sets andthe second interconnecting member.
 21. The transmission of claim 20wherein the first planetary gear set includes a set of long pinion gearsrotatably supported by the common carrier member and meshes with each ofthe sun gear of the first planetary gear set and the common ring gear.22. The transmission of claim 21 wherein the second planetary gear setincludes a set of short pinion gears rotatably supported by the commoncarrier member and meshes with each of the sun gear of the secondplanetary gear set and the set of long pinion gears of the firstplanetary gear set.
 23. The transmission of claim 24 wherein the firstplanetary gear set is disposed between the second and the thirdplanetary gear sets and the first, second, and fifth of the five torquetransmitting mechanisms are disposed between the first planetary gearset and the third planetary gear set.
 24. The transmission of claim 23wherein the third and fourth torque transmitting mechanisms are disposedat a first end of the transmission adjacent the second planetary gearset.
 25. A transmission comprising: an input member; an output member;first, second and third planetary gear sets each having first, secondand third members, wherein the input member is continuouslyinterconnected to the first member of the first planetary gear set andthe output member is continuously interconnected to the third member ofthe third planetary gear set; a first interconnecting membercontinuously interconnecting the second member of the first planetarygear set with the first member of the second planetary gear set; asecond interconnecting member continuously interconnecting the thirdmember of the first planetary gear set with the second member of thesecond planetary gear set; a third interconnecting member continuouslyinterconnecting the third member of the first planetary gear set withthe first member of the third planetary gear set; a first torquetransmitting mechanism selectively engageable to interconnect the firstmember of the first planetary gear set with the second member of thethird planetary gear set; a second torque transmitting mechanismselectively engageable to interconnect the first interconnecting memberwith the second member of the third planetary gear set; a third torquetransmitting mechanism selectively engageable to interconnect at leastone of the second interconnecting member and the third interconnectingmember with the stationary member; a fourth torque transmittingmechanism selectively engageable to interconnect the third member of thesecond planetary gear set with the stationary member; a fifth torquetransmitting mechanism selectively engageable to interconnect the secondmember of the third planetary gear set with the stationary member, andwherein the torque transmitting mechanisms are selectively engageable incombinations of at least two to establish at least six forward speedratios and at least one reverse speed ratio between the input member andthe output member.
 26. The transmission of claim 25 wherein the firstmember of the first planetary gear set, the third member of the secondplanetary gear set, and the first member of the third planetary gear setare sun gears, the first and second planetary gear sets include acarrier member that includes the second member of the first planetarygear set, the first member of the second planetary gear set, and thefirst interconnecting member, and the second planetary gear set includesa ring gear that includes the third member of the first planetary gearset, the first member of the second planetary gear set, and the secondinterconnecting member, the second member of the fourth planetary gearset is a carrier member, and the third member of the fourth planetarygear set is a ring gear.
 27. The transmission of claim 25 wherein thefirst member of the first planetary gear set, the third member of thesecond planetary gear set and the first member of the third planetarygear set are sun gears, the second member of the first planetary gearset, the first member of the second planetary gear set, and the secondmember of the third planetary gear set are carrier members, and thethird member of the first planetary gear set, the second member of thesecond planetary gear set, and the third member of the third planetarygear set are ring gears.
 28. The transmission of claim 27 wherein thetransmission includes a common carrier member and a common ring gear,the common carrier member including the carrier members of the first andsecond planetary gear sets and the first interconnecting member, and thecommon ring gear including the ring gears of the first and secondplanetary gear sets and the second interconnecting member.
 29. Thetransmission of claim 28 wherein the first planetary gear set includes aset of long pinion gears rotatably supported by the common carriermember and meshes with each of the sun gear of the first planetary gearset and the common ring gear.
 30. The transmission of claim 29 whereinthe second planetary gear set includes a set of short pinion gearsrotatably supported by the common carrier member and meshes with each ofthe sun gear of the second planetary gear set and the set of long piniongears of the first planetary gear set.
 31. The transmission of claim 30wherein the first planetary gear set is disposed between the second andthe third planetary gear sets and the first, second, and fifth of thefive torque transmitting mechanisms are disposed between the firstplanetary gear set and the third planetary gear set.
 32. Thetransmission of claim 31 wherein the third and fourth torquetransmitting mechanisms are disposed at a first end of the transmissionadjacent the second planetary gear set.